On-platform notifications

[0xcrypto]

Along with email notifications, it would be cool to get notifications on the huntr.dev itself.

[psmoros]

It'd be cool to see a 'notifications' area on the huntr.dev website so that I don't need to check my emails or manually go through reports to find out if a maintainer/admin has commented on a report.

@michaellrowley

[psmoros]

+1 from michaell's duplicate issue